Pros: Free drinks and coffee, amazing discount, health benefits on part-time, you can sometimes feel like you're hanging out while making coffee on the side
Cons: Some stores open really early or are 24h, some store managers can change the feel, the occasional customer has an entitlement complex, wages aren't out-of-this-world (but many of the benefits offset the difference)
I loved my time at Starbucks, and I gained lots of valuable experience there. My manager was amazing, willing to help me grow and make sure I had a good work/life balance. He was always finding ways to help me grow, and the abilities I learned there are helping me in other positions now. The hardest part of the job is probably when a crazed customer wants life to be perfect, but they are few, unlike at a few other stores we could mention. On the flip side, I loved interacting with the customers and partners - I met lot's of neat people and gained some great relationships.
You may hear not-so-great experiences at Starbucks, but generally those are in the minority and because the store manager wasn't professional and didn't give the staff or customers time of day. Overall a great company, but definitely not my long-time career.